A Bumper Month of Clinical Trial News (NextGen Covid Vax Update)

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Image by Hilda Bastian, CC BY-NC-ND 4.0

It was a big month for clinical trials of next generation Covid vaccines. An exciting phase 1/2 trial in Africa for an intranasal vaccine designed for low-resource communities has been fully recruited, bringing the number of mucosal Covid vaccines that have reached clinical trial to 36. We also got results for a pancoronavirus vaccine from the UK, as well as the registration of a second phase 1 trial for another in Europe, and another is expanding recruitment to another city in Australia.

The Covid human challenge consortium reached a milestone—full recruitment of the Omicron infection study—and I have included an overview of all Covid human challenge studies. There are also 8 preclinical reports for next generation Covid vaccines this month, mostly for intranasal vaccines.

This post begins with my watchlist of next generation Covid vaccines advancing into mid- or late-stage trials. There are 9 vaccines in this list, with updates for 2 of them this month. After that, I have vaccine news broken down into the usual 3 categories of next-generation vaccines (definitions below). Each section ends with an overview of vaccines in the category – and each has a link to skip over that straight to the next news section. In addition, there are tables tracking mucosal vaccine trials and pancoronavirus vaccines on my personal website.

ICYMI:

• An introduction to self-amplifying mRNA, plus my compendium on getting ready for more mRNA fear-mongering.
• Check out my May 2024 post, “When will we get a sterilizing Covid vaccine?”

• Watchlist of featured vaccines
• Mucosal vaccine news
• Durable or “variant-proof” vaccine news
• Pancoronavirus vaccine news

• Addendum 1: List of authorized vaccines (with countries)
• Addendum 2: Definitions of vaccine types
• Addendum 3: Table of mucosal vaccines in clinical trials (here—off this blog)
• Addendum 4: Table of pancoronavirus vaccines with preclinical results (here—off this blog)

• Postscript: US Project NextGen funded trials

Watchlist of featured vaccines

There are some updates to this section this month:

• SK Bioscience will begin recruiting participants from Sydney as well as Perth in their phase 1/2 trial for their protein subunit pancoronavirus vaccine. (It is based on a vaccine that had already gained approval in South Korea and the UK.) (Contact details here.)

• Vaxart pushed back the planned release of phase 2b results a little—to early 2027.

(Click here to skip ahead to next section.)

This watchlist includes vaccines in advanced development, which currently appear to be progressing more than others, based on publicly available information. I have sorted them into several groups, starting with the most advanced prospects. Which vaccines make this list is very likely to change from month to month. For example, the Arcturus self-amplifying mRNA vaccine is not on this list, even though additional authorizations have been planned for it internationally. That’s because the impact of changes in the US have set it back, and there hasn’t been an update about the implications for further rollout.

I am currently featuring 9 vaccines:

[A] Vaccines in mid- to late-stage trials, with manufacturing partners or planned production facilities—3 vaccines (including 1 mucosal) from Japan, the US, and South Korea (VLP Therapeutics, Vaxart/Dynavax, DV&VX);

[B] A vaccine in advanced mid-stage trials—for people with immunocompromise, from the US (Geovax);

[C] A vaccine adapted from a Covid vaccine that has already been approved in South Korea (SKYCovione); and

[D] Vaccines in mid-stage trials with recent public progress—4 vaccines (all mucosal) from Canada, the US, and France.

A. Vaccines in mid- to late-stage trials with manufacturing prospects:

Self-amplifying mRNA vaccine from VLP Therapeutics Japan:

This development program has been moving rapidly, adapting the vaccine to emerging variants in Japan. It is a self-amplifying mRNA vaccine, which can be more durable than first-generation mRNA. (My explainer on this vaccine type here.) The developer, VLP Therapeutics, is based in the US and Japan. They have been receiving funding support from the Japanese government for this vaccine, and I do not know if there are plans for making the vaccine available in other countries. VLP Therapeutics has also received private backing, developing manufacturing facilities in Japan.

I’ve listed all the clinical trials for this vaccine in the following table. VLPCOV-1 targeted the original strain of Covid, VLPCOV-2 was adapted for the Gamma variant, and versions 4 and 5 were adapted to Omicron variants.

Results have been published for a phase 2 trial of VLPCOV-2, which was compared to an Omicron-adapted version of the BNT/Pfizer vaccine. The VLP vaccine had similar results, even though it had the disadvantage of not being adapted to Omicron.

At the end of March, a phase 1 trial was registered for a “universal” Covid version of the vaccine. This latest version of the vaccine is called VLPCOV-U-1, and it is a T-cell-inducing vaccine aimed at a part of the virus that has not mutated in new Covid variants. T-cell-inducing vaccines don’t rely on developing antibodies, but develop T-cells to eliminate virus-infected cells.

Over 10,000 people have been recruited to phase 3 trials for the Omicron versions. Given the speed at which this development program has been moving, it might not be long until we get the first phase 3 trial results.

(All records in my collection for this vaccine here.)

Phase	Trial status	Participants	Register record	Results reported
VLPCOV-1
1	Begun 2021; completed.	Booster dose in 45 adults.	jRCT2071210067
1	Begun 2022; completed.	Booster dose in 92 adults.	jRCT2051210164	August 2023
2	Begun 2022; fully recruited.	Booster dose in 300 adults.	jRCT2051220087
VLPCOV-2
1/2	Begun 2023; completed.	Booster dose in 96 previously vaccinated adults (phase 1); 323 adults in phase 2.	jRCT2051230005	February 2024 (Phase 1) February 2026 (Phase 2)
VLPCOV-4
3	Begun 2023; fully recruited.	Booster dose in 2,000 adults.	jRCT2051230141
3	Begun 2024; fully recruited.	Booster dose in 2,000 adults.	jRCT2051230178
VLPCOV-5
3	Begun 2025; fully recruited.	Booster dose in 6,200 adults.	jRCT2031240751
VLPCOV-U-1 (“Universal” Covid)
1	Begun 2026; recruiting in Japan.	Booster dose in 80 adults.	jRCT2051250250

Oral viral vector vacccine from Vaxart and Dynavax (USA):

This mucosal vaccine comes in tablets, and it is based on an adenoviral vector. Vaxart expects to release the 12-month results for the first 400 people in its large phase 2b trial by the middle of this year, with the first results for the other 5,000 people early in 2027. Late last year the company announced that, pending positive phase 2b results, Dynavax will be their global manufacturing partner. Then at the end of year, drug manufacturing giant Sanofi acquired Dynavax.

I’ve listed their clinical trials in the following table. They have released so far from their phase 2a trial so far, indicating that the vaccine induced additional mucosal immunity in people who had previously been vaccinated with mRNA.

(All records in my collection for this vaccine here.)

Phase	Trial status	Participants	Register record	Results reported
1	Begun 2020; completed.	Booster dose in 40 adults.	NCT04563702	July 2022
2a	Begun 2021; completed.	Booster dose in 66 adults.	NCT05067933	Brief report: September 2022 press release.
2b	Begun 2024; fully recruited.	Booster dose in 5,400 adults.	NCT06672055	(Expected in late 2026.)

Virus-like particle vaccine from Stanford University and DX&VX (USA, South Korea):

DV&VX announced that they are accelerating this vaccine’s development, planning to start a global phase 2 trial early this year. They have indicated interest in developing a mucosal version of the vaccine. It’s a ferritin-based virus-like particle vaccine, using nanoparticles to modify the proteins.

The developers at Stanford aimed for a low-cost vaccine stable at room temperature, that would not be vulnerable to changing Covid variants—another “universal” Covid vaccine. It is also expected to have yearly boosters.

Their clinical trial program is in the table below.

(All records in my collection for this vaccine here.)

Phase	Trial status	Participants	Register record	Results reported
1	Begun 2023; completed.	Booster dose in 121 adults (USA).	NCT05870839
1	Begun 2023; completed.	Booster dose in 130 adults (South Africa).	NCT05938075
2	(Expected in early 2026.)

B. Vaccine in advanced mid-stage trials:

Viral vector vaccine for people with compromised immune systems, from the City of Hope and Geovax

This is the only advanced next generation Covid vaccine designed for better protection of people with immunocompromise and others at high Covid-risk. (Arcturus is also running a phase 2 trial of their self-amplifying mRNA vaccine.) This is one of the vaccines that faced a setback when the US government canceled Project NextGen support. Geovax has reported that it is seeking partners to take the vaccine forward.

The City of Hope/Geovax vaccine has outperformed mRNA vaccine in people with immunocompromised in their trials: a table of their trials follows. The viral vector is modified Ankara virus (MVA).

(All records in my collection for this vaccine here.)

Phase	Trial status	Participants	Register record	Results reported
1 to 2	Begun 2020; completed Dec 2025	Booster shot (escalating doses) in 119 healthy adults	NCT04639466	Phase 1 (56 participants)
2	Begun 2021; fully recruited.	2 dose regimen in 63 adults with blood cancer who have received stem cell transplant or cellular therapy (compared with mRNA vaccine)	NCT04977024
2	Begun 2023; still recruiting for experimental arm only.	1 dose in 80 adults with chronic lymphocytic leukemia (CLL) (initially compared with mRNA vaccine, but control group discontinued because of lack of effect)	NCT05672355

C. Adapted version of an already-approved vaccine:

Protein subunit unit pancoronavirus vaccine from SK Bioscience (South Korea)

A phase 1/2 trial for 368 participants has only just started for this vaccine in Australia. However, as it is an adapted version of a Covid vaccine that had already achieved authorization (marketed for a time as SKYCovione), it begins with the advantage of an established research base that may speed it up down the line. This month, the trial expanded to Sydney as well as Perth. (Contact details here.)

This vaccine was originally developed by the University of Washington in Seattle. The original vaccine was shown to provide some protection against other sarbecoviruses in animals, leading to the development of a pancoronavirus version of the vaccine.

(All records in my collection for the original version of this vaccine here, and for the pancoronavirus version here.)

D. Vaccines in mid-stage trials with recent public progress:

There are 4 mucosal vaccines in this group, that have yet to announce manufacturing partners:

• Aerovax: This aerosolized viral vector vaccine (adenovirus) is being developed by McMaster University in Canada. The phase 2 trial began recruiting participants in March 2025, and is still recruiting at McMaster. (All records on this vaccine here.)

• Castlevax: This intranasal viral vector vaccine (Newcastle disease) has been authorized in some countries in injected form. The vaccine was developed by the Icahn School of Medicine at Mt Sinai in New York. The phase 2 trial began dosing participants in November 2025, and is recruiting in Colorado and Massachusetts. (All records on the US development of this vaccine here.)

• CyanVac and Blue Lake Biotech: This is an intranasal viral vector vaccine (parainfluenza), and it was developed at the University of Georgia. A phase 2b trial for this vaccine was fully recruited by November 2025. (All records on this vaccine here.)

• University of Tours and LovalTech: This is an intranasal protein subunit vaccine, developed with French government support. Phase 1 of a phase 1/2 trial finished dosing in May 2025, and LovalTech is seeking additional financial support: Phase 2 may not begin this year.

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Mucosal vaccine news

This month, I have added another mucosal vaccine in a phase 1 trial, bringing the number of mucosal vaccines in my collection that have reached clinical trial to 36. Plus, the international human challenge consortium for mucosal vaccines, MUSICC, hit an important milestone, and I have included an overview of all registered Covid human challenge studies. There are also 5 new preclinical reports.

Intranasal live attenuated vaccine from National Institute for Medical Research (United Republic of Tanzania)

This vaccine, TANCoV, has been designed for the needs of low-resource communities. It is thermostable (requiring no refrigeration), and administered by nasal drops. It is a live attenuated vaccine based not on the SARS-CoV-2 virus, but on an avian coronavirus that does not cause disease in humans. A detailed protocol has been published for a phase 1/2 trial, that has already been completed. (The trial was registered here in 2022.) The developers report that it has been shown to induce immunity in several animal species—preclinical reports have not yet been published.

The trial is assessing safety, tolerability, and immunogenicity of TANCoV in 2 different doses, with one group also having a booster. Acceptability of the vaccine will also be evaluated: In-depth interview and questionnaire studies of a sample of participants is embedded with the trial.

The trial has completed vaccination in 169 participants in the Dar es Salaam and Mbeya regions of Tanzania. They are in 3 groups, each with a TANCoV arm and a control arm (the inactivated Covid vaccine from Sinopharm):

Group 1. Intranasal TANCoV (100 μL) and a saline injection, followed by a booster of another intranasal dose of TANCov at 28 days. The control arm was intramuscular Sinopharm vaccine and 100 μL of intranasal saline, followed by a booster of another dose of intramuscular Sinopharm.

Group 2. Intranasal TANCoV (100 μL) and a saline injection, followed by another saline injection at 28 days. The control arm was the same as for Group 1.

Group 3. Intranasal TANCoV (200 μL) and a saline injection, followed by another saline injection at 28 days. The control arm was intramuscular Sinopharm vaccine and 200 μL of intranasal saline, followed by a booster of another dose of intramuscular Sinopharm.

Unfortunately, I had missed this trial when it was registered. On the plus side, that means we should not have to wait long to see the results.

Covid human challenge study update

This month, the MUSICC consortium announced that their human challenge test of a version of Omicron (BA.5) had completed enrolment. (For a recap about the MUSICC project, see my 2024 post.)

The following table gives an overview of the Covid human challenge tests so far. These have been preliminary tests to develop the methods needed to run trials of Covid mucosal vaccines. No word yet on which vaccine(s) might be tested.

Trial	Purpose	Status
COVHIC001 [Registry record]	Tested a version based on the original SARS-CoV-2 in 36 people in the UK.	Completed and published (2022).
COVHIC002 [Registry record]	Tested a version based on the Delta variant in 46 people in the UK.	Completed.
COVCHIM02 [Registry record]	Testing a version based on Omicron BA.5 in 36 people in the UK.	The first MUSICC trial. Full recruitment announced in May 2026.
Sing-COV [Registry record]	Testing the version based on the Delta variant in 20 people in Singapore.	Fully recruited.

Preclinical reports:

• Live attenuated intranasal vaccine from the Friederich Loeffler Institute (Germany) and the University of Bern (Switzerland): This is the third report for this vaccine. Previous preclinical work found that the vaccine could not completely prevent transmission of Omicron XBB.1.5. The vaccine was adapted to incorporate that variant, and called OTS-300. It was tested in hamsters. Some hamsters were vaccinated with the intranasal OTS-300 vaccine, some were injected with an mRNA vaccine, and some received a mock vaccine. All were challenged with the XBB.1.5 variant. None of the animals died of the infection, but the mock-vaccinated hamsters lost weight, while the mRNA-vaccinated ones did not. The OTS-300 hamsters gained weight, and little virus could be detected in their nasal passages or lungs.
  
  To test for transmission, the 3 groups of hamsters were co-housed with unvaccinated hamsters. There were some signs of virus in the animals co-housed with the OTS-300 group, but not enough for them to seroconvert. All hamsters in the mRNA and mock vaccine groups seroconverted.
  
  (All records for this vaccine here.)

• Intranasal mRNA vaccine from the National Institutes for Food & Drug Control, State Key Laboratory of Drug Regulatory Science (China): This is the first preclinical report for this vaccine. Intranasal or intramuscular vaccination alone was compared with combination regimens in 2 types of mice. The mice were challenged with the Delta variant. The only regimen that provided adequate systemic and mucosal immunity was intramuscular prime followed by intranasal boost.

• Intranasal nanoparticle vaccine from the Centre for Drug Delivery Technology and Vaccine (CENTRIC) (Malaysia): This is the first preclinical report for this vaccine. The vaccine was tested in mice in intranasal, intramuscular, and combination regimens. The developers concluded that intramuscular prime followed by intranasal boost induced stronger signs of immune response than either method alone.

• Intranasal virus-like particle vaccine from the Jiangsu Key Laboratory of Zoonosis, Yangzhou University (China): This is the first preclinical report for this vaccine. Versions of the vaccine with or without one of 2 flagellin adjuvants were tested in mice. The developers concluded that the vaccine with one of the adjuvants (trunculated flagellin) induced strong signs of systemic and mucosal immunity.

• Oral protein subunit vaccine from Tarbiat Modares University (Iran): This is the first preclinical report for this vaccine. Several versions, including a flagellin adjuvant, were tested in mice. The developers concluded that one of them induced strong signs of systemic and mucosal immunity.

Skip ahead to next news category

Mucosal Covid vaccine overview

• 5 mucosal vaccines are currently authorized for use, at least 1 in each of 6 countries. None have been authorized by a drug regulatory agency designated stringent, or listed, by WHO. However, each has been authorized by a regulator which has transitional WHO listing for vaccines.
• 36 mucosal vaccines have reached clinical trial, although some of the vaccines are no longer in development. The vaccines that have entered clinical trials are tracked in a table on my website. They are mostly viral vector vaccines.
• In addition to the 5 authorized mucosal vaccines, 6 have reached phase 2 trials, and another 2 have reached phase 2/3 trial.

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Durable or “variant-proof” vaccines

There were 2 preclinical reports for vaccines this category:

• mRNA vaccine from the National Centre for Biotechnology (CNB/CSIC) (Spain): This is the first report of an mRNA vaccine from this group: Previous versions have been DNA and viral vector (modified vaccinia Ankara), including some mucosal administration. It is based on several parts of the SARS-CoV-2 virus. The vaccine was tested in mice, providing complete protection in a challenge test. (All records for the vaccines in this development program here.)

• DNA vaccine from the University of Ottawa (Canada): A thesis was published on adjuvants in this “variant-proof” DNA vaccine. (All records in my collection for this vaccine here.)

Skip ahead to last news category

Durable or “variant-proof” vaccine overview

Note: This is a rather vague category, including vaccines that aim to be more durable. I’m not sure how many can be classified as aiming to be “variant-proof”.

Authorized vaccine:

There is 1 authorized vaccine in this category, and it has been authorized by several drug regulatory authorities designated by WHO has stringent, and tested against an mRNA vaccine (Kostaive):

• LUNAR-COV19 (USA), trade name Kostaive: This self-amplifying mRNA vaccine was authorized in Japan in November 2023, with rollout in October 2024. It was authorized for Europe in February 2025, and in the UK in January 2026.

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Pancoronavirus vaccine news

This month there were results from a phase 1 trial in England, and a second phase 1 trial beginning for a vaccine in France and Switzerland. And there was one preclinical report from China. In addition, as reported above, the phase 1/2 trial in Australia for SK Bioscience’s sarbecovirus vaccine has expanded recruitment to Sydney as well as Perth.

Phase 1 trial results for a DNA sarbecovirus vaccine from Cambridge’s DIOSynVax (UK)

This is a DNA vaccine aimed at sarbecoviruses, administered by a device that injects the vaccine below the skin. The phase 1 trial began in December 2021, with the final participants vaccinated in 2023—so the participants had very different levels of exposure to Covid across that time. The trial aimed to test vaccine tolerability and safety as well as evaluate dosage levels. There were 39 participants in the final safety results for the trial, all of whom had previously been vaccinated with other Covid vaccines: 6 were not included in the immunogenicity results because they had tested positive for Covid before full vaccination had taken effect.

No serious or severe adverse reactions to the vaccine were reported. Altogether, 15 people tested positive for Covid, though none were sick enough to require medical treatment.

For the immunogenicity analyses, blood was analyzed for signs of response to the sarbecovirus antigen in the vaccine, the original strain of Covid, and the original SARS; for 2 of the dosage levels, signs of response to Delta and Omicron BA.1 were also analyzed. The developers concluded that the responses were “modest and variable,” and lower for the original SARS than for Covid. Despite the low immune response in phase 1, the developers reported that a phase 2 trial is planned.

(DIOSynVax is a Cambridge University spin-off biotechnology company. All records on this vaccine here.)

Second phase 1 trial registered for protein subunit sarbecovirus vaccines from the INSERM Vaccine Research Institute (France)

INSERM is France’s National Institute for Health and Medical Research. They have registered a second phase 1 trial for their protein subunit vaccine. They plan to recruit 48 people in France and Switzerland (contact details here). Their first trial is still listed as recruiting. It is a phase 1/2 trial for up to 240 participants in France (contact details here).

Both of these trials are testing a booster in people already vaccinated for Covid. However, the new trial is testing 2 versions of vaccine, compared to boosters of either the BNT/Pfizer or Novavax vaccine.

(All records on this vaccine here.)

Preclinical report:

This is a nanoparticle chimeric vaccine, from BGI College and the Henan Institute of Medical and Pharmaceutical Sciences at Zhengzhou University (China). In this first preclinical report, the developers report on the vaccine’s development and tests in mice. They concluded that the vaccine elicited signs of immune response to the original SARS-CoV-2 strain and Omicron BA.5, as well as to coronaviruses that were not included in the vaccine.

Pancoronavirus vaccine overview

A table at my website keeps track of vaccines I’ve added to this category so far that have publicly available preclinical results. Of these vaccines, 8 have reached phase 1 clinical trials, and 1 has reached phase 2. Some of them have released some results, and they are marked *:

• * CoronaTcP (Gylden Pharma, UK/US) – protein subunit. (Note: This vaccine was previously called PepGNP-SARSCov2, and the manufacturer was previously called Emergex.)

• * DIOSynVax (Cambridge University spin-off, UK) – DNA.
  
  
• Duke University (USA) – protein subunit.
  
  
• INSERM/Ennodc (formerly LinkInVax) (France) – protein subunit.
  
  
• Osivax (France) – protein subunit.
  
  
• SK Bioscience (South Korea) – protein subunit.
  

• * VBI Vaccines (Canada) – eVLP. [This company announced bankruptcy in late 2024.]

• * Walter Reed Army Institute of Research (WRAIR, USA) – protein subunit.

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Addendum 1: List of authorized next generation Covid vaccines (with countries)

There are 7 authorized next-generation Covid vaccines. Only one has been approved by drug regulatory agencies designated stringent, or listed, by WHO – in bold; the others have all been approved in at least one country by a drug regulator WHO has listed with transitional status for vaccines. I’ve listed the vaccines in 2 categories, in order of date of first authorization (or initial approval).

Mucosal:

• Razi-Cov Pars (Iran), intranasal protein subunit vaccine: Iran (October 2021).
• Sputnik (Russia), intranasal viral vector vaccine: Russia (April 2022).
• Convidecia (China), inhaled viral vector vaccine: China (September 2022), Morocco (November 2022), Indonesia (March 2023).
• iNCOVACC (USA/India), intranasal viral vector vaccine: India (September 2022).
• Pneucolin (China), intranasal viral vector vaccine: China (December 2022).

Durable or “variant-proof”:

• Gemcovac (India), self-amplifying mRNA vaccine: India (June 2022).

• Kostaive (LUNAR-COV19) (USA), self-amplifying mRNA vaccine: Japan (November 2023), European Union (February 2025), UK (January 2026).

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Addendum 2: Definitions of vaccine types

• Mucosal vaccines: These enter the body the way the virus does – through mucosal tissues. It’s hoped that provides defence against infection. They can be administered via different routes – squirts or drops in the nose, inhaled through the mouth through a nebulizer (similar to an asthma medication), or in tablet, capsule, or sublingual form.

• Pan-SARS-CoV-2 or “variant-proof” vaccines: These aim to provide protection against any variant of the coronavirus that causes Covid-19.
  

• Pancoronavirus vaccines aim to protect against coronaviruses more broadly – sometimes called “universal coronavirus vaccine.” These vaccines can be targeted to:
  
  – the “subgroup” the 2 SARS viruses came from (the sarbecovirus subgenus),
  
  – coronaviruses from the next level up (the genus, betacoronavirus, which includes MERS as well as the sarbecoviruses), or
  
  – up to the whole coronavirus family, which has 4 genuses, including betacoronavirus and alphacoronavirus (with more common cold viruses).
  
  I classify a vaccine as a pancoronavirus one when the developers are explicitly targeting coronaviruses more broadly than SARS-CoV-2 in the design of the vaccine, and have tested for signs of response to non-SARS-CoV-2 coronavirus(es) (or clearly plan to).

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You can keep up with my work at my newsletter, Living With Evidence. And I’m active on Mastodon: @hildabast@mastodon.online and less so on BlueSky (hildabast.bsky.social).

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Disclosures: My interest in Covid-19 vaccine trials began as a person worried about the virus, as my son was immunocompromised: I have no financial or professional interest in the vaccines. I have worked for an institute of the NIH in the past, but not one working on vaccines. More about me.

The cartoon is my own (CC BY-NC-ND license). (More cartoons at Statistically Funny.)

For details on how I track Covid vaccine progress, see my background post. Notes on my collection of studies are here. The collection is in a public Zotero library you can dig into here.

Previous update posts specifically on next generation Covid vaccines prior to this monthly series (beginning May 2023):

1. Mucosal vaccines (March 2022)
2. Pan-SARS-Cov-2 and pancoronavirus (July 2022)
3. Mucosal vaccines (July 2022)
4. Mucosal vaccines (September 2022)
5. Mucosal vaccines (April 2023)
6. Pancoronavirus vaccines (April 2023)

All my posts on Covid vaccines, beginning from March 2020, are tagged here.

All previous Covid-19 posts at Absolutely Maybe

My posts at The Atlantic and at WIRED.

Postscript: US Project NextGen funded trials

Mucosal vaccines:

• Phase 1 for MPV/S-2P, the intranasal viral vector vaccine developed by the NIH’s National Institute of Allergy and Infectious Diseases (NIAID). This trial for 60 participants began recruiting in July 2024, and finished recruiting by early 2025.

• Phase 2b for the oral viral vector vaccine from Vaxart (trial start announced at the end of September 2024; trial registration here) – further recruitment for this trial was cancelled, though followup will be completed for the participants already dosed (around 5,000). The company has a deal with Dynavax to take the vaccine forward, depending on phase 2 trials.
• Phase 2b for the intranasal viral vector vaccine from CyanVac/Blue Lake Biotech (trial started in December 2024, trial registration here) – no recent news on this trial.

• 2 trials are apparently not going ahead: A Phase 2b (“mini-efficacy”) for the intranasal protein subunit vaccine from Castlevax – this grant was paused and may be terminated. Castlevax has since registered a far smaller phase 2a trial with some similar methodological features. Another for the intranasal live attenuated vaccine from Codagenix had not apparently started.

Durable or “variant-proof” vaccines:

• Phase 1 for STX from Capricor (trial began dosing participants in August 2025). Capricor announced in November 2025 that the trial is ongoing.

• Phase 1 for TNX-1800 from Tonix (aiming for lifelong immunity) (planned to go into clinical trial in 2024 – no recent news);

• Funding was terminated for the Phase 2b (“mini-efficacy”) trial for GeoVax (viral vector vaccine).

Note: Gritstone Bio was originally in line for a phase 2b trial for their self-amplifying mRNA vaccine. However, the company declared bankruptcy and in January 2025, their assets were sold.

Pancoronavirus vaccines – presumed canceled:

• CoronaTcP (Gylden Pharma, UK/US) – protein subunit.
• Unnamed (PopVax, India) – mRNA.

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